


Magnificent - Sans(US)/Papyrus(US)

by SerifSinclair



Category: Undertale (Video Game)
Genre: And Ecto-Tongues, Dominant Sans, Fluff, Incest, Just Ecto-Tentacles, Love, M/M, My First Smut, No Ecto-Penis (Undertale), Soul Sex, Submissive Papyrus, Swapcest - Freeform, Tentacles, Undertail, happiness
Language: English
Status: Completed
Published: 2016-10-20
Updated: 2016-10-20
Packaged: 2018-08-23 13:00:12
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,775
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8328883
Author URL: https://archiveofourown.org/users/SerifSinclair/pseuds/SerifSinclair
Summary: Sans returns from a day of work and play with Alphys to Papyrus. Papyrus is happy to see his brother return home - and that his brother is very 'happy' to see him as well. Sans decides to put into play something new he learned today...Prepare for affection, fluff, tentacles, soul-sex, and technically light bondage.





	

“Papy!” Sans cried as he lunged for his brother, tackling into him and driving the sweater-clad skeleton back several steps.

“Heya, Sans. Welcome home,” Papyrus said with a smile, arm coming up to cradle Sans to his chest, supporting the smaller skeletons weight. “Have fun hanging out with Alphys today?”

Sans giggled as he nuzzled into Papyrus’ neck. “Yup! After patrol, we went back and watched a bunch of episodes of anime.”

Papyrus arched a browbone, tilting his head to allow Sans greater freedom, enjoying the gentle warmth and sensation of bone on bone. “Was it that kitty-cat anime again, Meow-Meow or something like that?”

Sans licked the delicate bones of Papyrus’ neck, cool blue tongue slowly sliding against the bone-white vertebrae. A shudder ran through the taller skeleton’s body, and he reached up a hand to cup the back of San’s head. “Nya~” Sans practically purred as he teased his brother. “We actually watched something else today…” he trailed off, and Papy missed the calculating gleam that entered his starry eyes.

“Y-yeah?” Papyrus managed, eyes closed as he basked in the feel of his brother licking and lightly sucking at his neck. “Was it something interestin’, instead?” Giving up on standing, Papyrus stumbled back to collapse on the couch, keeping Sans cradled close the entire time. Sans kept his balance easily, well-used to using his brother as a perch, and used the momentum to latch onto Papyrus’ clavicle.

Sans snickered through lightly clenched teeth as Papyrus gasped, knowing full well how sensitive Papyrus’ bones could be. He relented and let go so he could answer the question, leaving behind faint imprints of his teeth. “You could say that~” he sing-songed, hands coming up to cradle Papyrus’ face. The scheming skeleton trapped the other in a deep kiss, quickly distracting them both from the conversation. Orange and blue swirled together, a magical dance of tongues that slid sensuously around each other.

Sans leant forward, chasing Papy’s orange tongue into his mouth, licking at the backs of his teeth and around his jaw. Papy was helpless to stop Sans, tongue curling around the one currently invading his mouth. Sans opened his eyes to see that Papyrus’ eyes were closed, clearly savoring the sensations within. Sans couldn’t help hide the wicked grin that twisted the corners of his mouth as he began enacting his plan.

Magic began to take on an only barely familiar shape, twisting in the air around them both in a facsimile of his tongue’s movements – the tongue he was using to keep Papyrus distracted and not noticing the change. Sans tested the new limbs, ensuring that he had proper control and that he’d created them with the right width and taper. He let a tendril slide through his own open hand, twisting it around his fingers with pure control over the magic.

Yes. He was ready.

Papyrus moaned as he felt Sans running hands along his ribs, fingers dipping between each bone and pressing against the invisible magic field that served to protect his bones from the outside world. He clearly felt each dip and divot that Sans took, caressing each bone in a careful grasp. He broke free of their kiss and pulled back, panting, as Sans dipped another hand into his cargo pants, pulling the fabric down and away from the bone.

He blinked in confusion as he realized too much was going on at once, and lifted his head to see what was happening. A deep moan built low in his throat as he realized that what he thought were fingers were actually tentacles, tentacles that began winding their way through his torso. He was frozen in place as they slid through his ribs, starting at the floating ribs and curving around them in a loop before doing the same with the next rib, and the next. Soon, he had tentacles looped through all of his ribs, winding around bone on and never ceasing in their movements. There were two on his left side and one on his right, all moving at different paces and pulling tight with different strengths.

The two outer tendrils didn’t stop at his torso, reaching up until they wrapped around his lower jaw. His mouth was tugged open, and orange drool began to leak helplessly from the sides. He whined as he realized what a display he must make, just lying back and letting his body be violated by his brother’s tentacles. Tentacles that weren’t even fully visible – they’d crept up from under his sweatshirt, creating tantalizing bumps in the fabric that hinted at just what was happening beneath.

It was a sight Sans clearly wanted to see, as the younger skeleton’s next move was to rip Papyrus’ hoodie off with his bare hands. It was at that moment Papyrus noticed that he had been stripped of all his clothes, his pants disappearing at some point while he’d been distracted with the tentacles writhing around in his ribs and filling his ribcage. “Oh, Papy,” Sans breathed. “You look magnificent.”

Papyrus couldn’t help the moan as he tried to respond, the tentacles holding his jaw in place keeping any words from escaping. He shuddered helplessly as Sans leaned in close, licking up the saliva that was slowly dripping down his chin. Papyrus tried to catch Sans tongue with his own, but one of the tendrils reached out and caught it instead. Sans did join in a moment later, and then there was a three-way battle taking place in Papyrus’ mouth.

He attempted to reach up and pull Sans closer, but he couldn’t move his arms. He tugged again, and felt the same resistance that was pressing on his ribs – more tentacles had wound their way around his arm, threading themselves through his ulna and radius, bending his arm back until his hand was trapped against his own shoulder and his elbows were tucked against his sides.

He was bound, immobile and helpless as Sans ravaged his mouth. He’d never been more turned on in his life, as the insistent orange glow in his chest would show. He shivered in pleasure as the tendrils insisted on his attention, sliding around in his rib cage just as his brother’s tongue slid around in his mouth. He finally realized what the third, almost unnoticed tendril in his chest was for as it reached inside and wrapped around his soul.

All he could feel was love and warmth, heat and desire, lust and love, happiness and anticipation, so much love; his emotions and his brother’s, brought to his attention by the source of his magic, the center of his being. He was wrapped up in a warm hug, cocooned by his brother’s magic. He could feel Sans delight at his response, how debauched he looked, how open he was to whatever Sans wanted to give him. He could feel the burning heat of need twisting through his being, driving his pleasure so much higher. He could feel his brother’s own soul-deep arousal, twinning with his own.

He could feel it all as his soul was squeezed by Sans’ magic, wrapping around and around until no sight of orange could be seen, entirely hidden by blue. It pulled tighter around his heart, tighter around his bones, tighter through his mouth, tighter around his tongue, tighter at all that he was until he was bursting, screaming as his pleasure peaked. He felt an echoing response, drenching him in overflowing magic as they both came.

Slowly, Sans drew back, licking at his teeth to catch every trace of Papy before he left. The tendrils retreated very gradually, releasing his mouth which slid shut with a resounding click as it snapped back into place. Papy shuddered as they slowly unwound from his ribs and his arms, all but one of them pulling away.

He could still feel Sans tight around him, knew that he was still clutched within Sans’ grasp. Even as the rest of Sans’ magic pulled away, the one wrapped around his soul remained, unwilling to leave and sever their connection. Papyrus almost told Sans to take the soul with him, carry Papyrus around with him wherever he went. He would have, if he wasn’t already so exhausted, but Sans sensed the desire anyways.

In return he felt the whisper of a promise, an idea saved for another day. Finally, finally they both relaxed their grip, and the manifestation of Sans’ magic slowly pulled away. Papyrus felt wetness trail along his ribs, and saw glowing orange and blue being painted through them as the tendril unwound itself. Sans reached forward, swiping a finger through their combined magics and forcing a wheezing gasp from Papyrus at the sensation of training-roughened bone against his overly-sensitive bones.

He watched with love in his heart and warmth in his body as Sans licked at the phalange, humming happily as he tasted the rewards of their effort. The tendril still coated with his juices approached Sans mouth, and Papyrus could only watch as Sans devoured it like a tasty morsel, sucking along it’s blue length and chasing down every hint of Papyrus’ orange magic. The tendril was only to happy to comply, sliding into Sans mouth and down his throat, blue glow visible through the translucent barrier of Sans throat. Sans swallowed convulsively as the tendril slowly dissipated.

Papyrus slowly leaned forward, wrapping his arms around the smaller skeleton once more. This time it was he that tucked his head into the others neck, nuzzling just under where ears would be if either skeleton had them. “That was amazing, bro. Thank you.”

Sans turned and gave Papyrus a chaste peck, bone clicking together harmoniously before he spoke. “Anything for you, Papyrus. You were so good for me…” he trailed off, licking at a speck of magic he had missed earlier. “Mmm, you always taste so good…”

Papyrus shuddered as a wave of warmth swept through his system, aroused by his brother’s actions and compliment. “’s the honey, bro. It’s the only way I can be as sweet as you.”

Sans laughed as he pulled back, smiling at his brother. “It’s not the honey that makes you so sweet; that’s just who you are!” Papyrus felt his soul glow with pride and hugged Sans even tighter.

“Thanks, bro, but you’re still the most magnificent thing I know.” Papyrus loved his so much, the fun they’d had earlier and the easy love they were sharing between themselves now.

“Mwe-he-he!” Sans half laughed, half cheered. “Well, I am the Magnificent Sans!” He pulled back to pose, and Papyrus laughed along with him. Stars above, he loved his brother so much.

**Author's Note:**

> Thank you, 0netype, for continuously encouraging me to post these publicly, and for supporting me when I do so. Thank you, anybody who reads this, for the time you gave to me. Thank you, in advance, for hopefully being respectful and not leaving inflammatory or hateful comments. This, and other stories that I shall post, go up on my tumblr blog first - [SerifSins](http://serifsins.tumblr.com/) \- and I heartily encourage you to check it out if you like what I've written! There's also the rare reblog and slightly more common commentary for me, and I'd be happy to answer anybody's asks there if they have any.  
> Or, you could leave your question in the comments below. In fact, I would love it whether or not you told me if you enjoyed it, and what you might like to see more of. :)


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